1. Field of the Invention
The present invention relates to an outdoor unit of an air conditioner, and more particularly, a fan shroud for that unit. The fan shroud allows air to flow smoothly through the outdoor unit.
2. Discussion of the Related Art
An air conditioner, using the refrigeration cycle, compresses, condensates, expands and evaporates to control ambient air a refrigerant temperature and humidity. Generally, the air conditioner, with various devices for refrigeration cycle is divided into an indoor unit and an outdoor unit. The indoor unit contains an evaporator that evaporates a liquid refrigerant, to cool the ambient air. A condenser, which condenses the refrigerant from vapor into liquid, is the major element in the outdoor unit.
FIG. 1 illustrates a cross section of an outdoor unit with a conventional fan shroud.
Referring to FIG. 1, the outdoor unit 2 contains a motor 4, a fan blade 6, and a heat exchanger 8. The motor 4 drives the fan blade 6 to cause air to flow over the heat exchanger 8. That is, the air flows into the outdoor unit through rear side via the heat exchanger 8 thereof by rotation of the fan 6, and flows out of the outdoor unit through front side thereof. A fan shroud 10 is located in front of the fan 6 as an air discharge passage, and a grill 12 located in front of the fan shroud 10 protects the unit. The conventional fan shroud 10 has a converging-diverging nozzle form, 10b and 10a. That is, an inflow portion 10a (on the fan side) of the fan shroud as well as an outflow portion 10b (on the grill side) have outwardly diverged forms. The outflow portion 10b has a greater diameter than the inflow portion.
The manner in which the conventional fan shroud operates will be explained by the referring FIG. 1. The refrigerant, vaporized in the evaporator (not shown) in the indoor unit, is compressed in the compressor (not shown), and then flows into the heat exchanger 8. The refrigerant in the heat exchanger 8 exchanges heat with outside air condenses, and flows back into the indoor unit. That is, the fan 6 rotates, pulling air into the outdoor unit through a rear side thereof, and exchanges heat with the refrigerant. The air, with its elevated temperature due to passing over the heat exchanger flows out of the outdoor unit through the fan shroud 10 and the grill 12.
The conventional fan shroud for an outdoor unit of an air conditioner has the following problems. The outwardly diverged inflow portion 10a of the conventional fan shroud 10 causes great vortexes at the outflow portion 10b, and with the vortexes, the turbulence noise increases making the entire noise of the outdoor unit greater. These vortexes in the downstream in turn reduce the air discharge area, which degrades the heat exchange performance.